1. Field of the Invention
The field of the present invention is decorative light strings.
2. Background
Decorative light strings are commonly used to produce visual effects at homes and in business locations around the holiday seasons. A light string that is bright and rich in flashing patterns will often strongly improve the holiday spirit of all who see it. Since light strings are limited in length, they are commonly connected together in series end-to-end when more decorating length is needed. Combining more strings together not only makes decorating easier, but it also makes decorating less expensive and time consuming since fewer electrical outlets and/or extension cords are required. When flashing or other patterns are desired, the light strings with controllers are required. However, when multiple light strings, with controllers, are connected in series, there will be a synchronization problem between the light strings, even when the same flashing pattern is used for each light string. The controllers simply have no feature which permits close synchronization between the light strings. Even powering the light strings simultaneously does not guarantee synchronization.
This synchronization problem is exacerbated when the flashing pattern is changed, because the user must go to the controller of each separate light string to change the settings individually, one at a time. Of course, when many different light strings are chained together in series, changing the settings of every single controller presents its own set of difficulties.
Other light strings attempt to get around the synchronization problem by using timed sequence patterns, thereby giving the appearance of synchronization. These timed sequence patterns are set to start at the beginning of each string when the string is first powered, so that connected strings have the appearance of synchronization. However, with such strings, the light pattern cannot be changed by the user, as the controller includes only the one pre-set pattern to always maintain the appearance of synchronization.
Other types of light strings allow the end user to change the pattern either with a remote control, or even have the lights flash to the beat of music. However, even with these types of light strings, when several are connected in series, the flashing patterns of the light strings are not actively synchronized, other than by happenstance, due to slight differences in the reference clock frequency at the controller of each light string. With more light strings used in a single space, regardless of whether they are connected together in series, the differences in reference clock frequencies will be exacerbated.